Written by Garett Reid | NSCA, CSCS, CISSN, M.S.E.S.S
Fact checked by Kirsten Yovino, CPT Brookbush Institute
FACT CHECKED
When reading the words "concentric vs eccentric", do you think of circles or muscle contractions? Or do you not think of anything at all? If you thought about muscle contractions and exercises, we are off to a good start.
Most people who go to the gym just want to get in shape and move on with their day. However, chances are that you want to be more serious about your gains and work on specific aspects of your body. In that case, you need to understand how your muscles work. That way, you can have more effective workouts.
One of the most important things you should learn about training for strength and hypertrophy is concentric and eccentric muscle contractions. So, here is a rundown on everything that you need to know about isometric, concentric, and eccentric exercises.
Before we dig into eccentric and concentric muscle contraction, we should first explain what an isotonic exercise is...
WHAT IS AN ISOTONIC EXERCISE?
An isotonic exercise simply means the muscle is producing contraction through movement.
It refers to how a muscle contracts and shortens through a range of motion while under tension from a load.
A simple example we can offer is that of a bicep curl with dumbbells. As you lift the weight (flex your elbow), you will contract the bicep muscle until you reach its limit of contraction/movement. And from there, you will slowly bring it back down (extend the elbow) until your arm is straight as it was at the beginning, thus lengthening the muscle. This completes a single repetition of the exercise.
Isotonic exercises can further be broken down into two different categories of concentric and eccentric movement. Concentric being the shortening phase and eccentric being the lengthening phase. We will dive into this shortly.
Another thing to note is that muscle can produce tension and contraction in another way, so let's quickly discuss that...
ISOTONIC VS ISOMETRIC EXERCISES
An isometric exercise is essentially the opposite of an isotonic exercise - it is muscle contraction without movement. It involves keeping your muscles in a fixed position for a set time while under tension.
A good way of visualizing it is by thinking about pausing at any point during an isotonic exercise and holding the position (i.e. holding your position midway through a push-up).
A few good examples of isometric exercises include different holds such as planks, side planks, wall sits. In all of these exercises, it is necessary for you to hold a specific position to engage different muscle groups.
Any exercise can be turned into an isometric exercise. All you have to do is hold your position. For example, holding a squat position when your thighs are parallel with the floor, holding a barbell deadlift when in the standing position, keeping your legs fully extended during a leg extension, etc.
It's not uncommon for trainees to include isometric elements into their isotonic workouts, such as holding the top of the pull-up position for 5-10+ seconds on the last rep.
WHAT IS THE DIFFERENCE BETWEEN CONCENTRIC AND ECCENTRIC CONTRACTION DURING EXERCISE?
An isotonic movement breaks down into two major phases: a concentric phase and an eccentric phase. In the simplest explanation, the concentric phase of a movement is when you are contracting (shortening) the muscle, and the eccentric is when you are lengthening the muscle.
So, when you perform, for example, a squat, the eccentric phase is when you are descending, as your quads and glutes will lengthen, and the concentric phase is when you start ascending to the standing position, as your quads and glutes will shorten.
This understanding can apply to any exercise or movement that you perform.
Examples of the concentric phase of an exercise
- Deadlift: When you lift the barbell off the floor, your hamstrings, glutes, and low back are contracting.
- Bench press: When you’re pushing the weight upwards, your pecs and triceps are contracting.
- Squats: When you are pressing up from the bottom of a squat, your quads and glutes are contracting.
A good tip to remember is that concentric is CONTRACTION. Or concentric as the positive. If you’re going against gravity in your exercise, it counts as a concentric movement.
Examples of eccentric phase of an exercise
- Deadlift: As you lower the weight back down from the standing position, your hamstrings and glutes lengthen while under tension. Remember, dropping or throwing the weight doesn’t count and can be actively harmful.
- Bench Press: As you lower the weight down toward your chest, your pecs and triceps are lengthening.
- Squat: As you lower down into the squat, your quads and glutes are lengthening.
A good tip to remember is that eccentric is LENGTHENING (aka STRETCHING) of the muscle. OR, eccentric as the NEGATIVE (you've probably heard of doing "negatives" before). If you are going with the flow of gravity, you will be performing an eccentric exercise.
DEADLIFT (CONCENTRIC & ECCENTRIC BREAKDOWN)
We already mentioned above how deadlifts function in terms of the concentric and eccentric movements. However, it is worth looking at both phases of the exercise in more detail. Specifically, we wanted to describe how the concentric and eccentric contractions go together to complete the exercise.
Concentric:
From a bent down position with your hands on the barbell, you will initiate the concentric phase of the exercise. This phase will mainly affect the back, glutes, and hamstrings. It is fairly straightforward. As you bury your feet into the ground and lift the weight, these muscles will start to contract.
You will eventually reach the final position of the concentric phase when the muscles are fully contracted (or nearly in full contraction). This is when you are standing upright.
Note: If you hold the top position for a few moments, you are employing an element of isometric contraction to the lift.
From here, you will move into the eccentric phase next.
Eccentric:
As you start to lower the barbell back down to the floor, your glutes, hamstrings and lower back will start to lengthen (stretch).
You will bend your knees (knee flexion) and push your hips down and back (knee flexion) until the weights touch the floor and you come to a deadstop. This ends the eccentric phase and completes one repetition of a deadlift.
Tip: A common mistake that most people make when performing deadlifts is that they tend to drop or dump the weight too fast. They will usually do this soon after the eccentric phase begins. Not only is this potentially dangerous as your muscles may be shocked and can lead to injury, but it makes the deadlift far less effective for building muscle. The eccentric phase is a crucial part of the deadlift. So, move as slowly as you can when lowering the weight down. It's ok to be explosive on the concentric phase, but be slow on the eccentric (unless you are specifically working on the concentric phase for power at that time, which we will get into later).
Related: Deadlift Guide - How To, Correct, Muscles Worked, & Variations
SQUAT (CONCENTRIC & ECCENTRIC BREAKDOWN)
Next is the squat, which is possibly the most popular exercise on this list. It is an exercise that almost every type of person performs, even if they specifically focus on calisthenics. The squat is a primal movement that we should all be able to do.
We aren't going to just breakdown the concentric and eccentric phases of the squat, but also how you can emphasize one or the other for specific training purposes.
For the squat, we are starting with the eccentric as the first part of the movement is the eccentric phase (unlike the deadlift).
Eccentric:
The eccentric phase starts as soon as you descend into the squatting position. Your glutes, hips, and quadriceps will lengthen and the lower you go, the more stretching tension they will receive.
Depending on the type of squat that you do, you will eventually reach your final position, which is around parallel or a little past paralell (which means where your thighs are in relation to the ground).
Note: Some squats tend to focus on slowing down the descending process. Making the descent slower emphasizes the eccentric phase and is a great way to build muscle and strength. It also makes the exercise significantly harder, no matter how much weight is being used.
Concentric:
From the bottom of your squat, you will press through the heels of your feet to a standing position. As you do this, your glutes, quads and lower back are contracting.
Note: Concentric-focused squats are where people rise very slowly. This increases time under tension and is also good for building muscle. Another option is to speed up the concentric phase to work on explosive power.
Related: Squat Guide - How To, Correct Form, Muscles Worked, & Variations
BENCH PRESS (CONCENTRIC & ECCENTRIC BREAKDOWN)
Finally, the last exercise that we will be looking at is the bench press, and how its eccentric and concentric process works. Unlike the other exercises that we just mentioned, a bench press can be very easy to pull off eccentrically. But it is during the concentric phase where people struggle the most.
Eccentric:
After you unrack the barbell, your arms will be fully extended your arms with the barbell suspended above you. From there, as you start to lower the barbell down toward your chest, the eccentric phase begins.
Your pecs, triceps, and deltoids will lengthen and the lower you go, the more they will lengthen.
Note: With dumbbells, you can increase the range of motion on the eccentric phase as you can go even lower than with a barbell, which will have no choice but to stop when reaching your chest.
The eccentric phase of a bench press is usually the easy part, as people rarely struggle to bring the weight down. However, the slower you go, the harder and more effective the movement will be for strength and hypertrophy.
Concentric:
Once you have the barbell on your chest, you will have to engage your pecs, triceps, deltoids, core, scapula stabilizer muscles, and even your lats to press the weight back up.
The entire process of pressing up from your chest until your arms are extended is the concentric phase.
If you are using lighter weight, you can slow down the concentric phase of a bench press, but if you are using a heavy weight load, there's not much you can do in the way of the concentric phase but do your best to get it up with good form.
Now, back to the eccentric phase, as there's some interesting things you can do with the bench press...
Your muscles are strongest in the eccentric phase, when lengthening, so you will be able to handle greater weight load on the eccentric phase than the concentric phase.
With that, lifters like to employ heavy negatives (negative = eccentric) occasionally. They will add more weight than they could handle on the concentric, but enough to really challenge them on the eccentric. and will reduce that weight on the back up. They will lower the bar down as slowly as they can with this heavy load, then when it's time to press it back up, spotters will help them enough so that they can complete the rep. This is a great way to emphasize the eccentric phase for the purpose of getting stronger and building more mass (you will get super sore!).
Related: Bench Press - How To, Correct Form, Muscles Worked, & Variations
UNDERSTAND THAT SOME MUSCLES WILL BE IN CONCENTRIC CONTRACTION WHILE OTHERS ARE IN ECCENTRIC CONTRACTION FOR ANY GIVEN LIFT:
When you are doing a specific exercise, you need to understand that you are performing concentric and eccentric movements simultaneously, meaning some muscles will be contracting while others lengthen. Therefore, there is no way that you can view these movements separately.
For example, if you were to curl your bicep, they would now be in a concentric motion but your triceps would be in an eccentric motion.
That said, the point of separating the two really comes down to the primary movers of the exercise. So, while the tricep is in contraction as the bicep lengthens during a bicep curl, it is not doing so against gravity.
When you are choosing your exercises, be sure to consider how different muscle groups will be working. By considering these factors carefully, you can then choose which muscle groups to focus on.
CONCENTRIC VS ECCENTRIC EXERCISE MUSCLE CONTRACTION, WHICH IS BETTER?
Fundamentally speaking, exercises will make use of concentric and eccentric contractions to some degree regardless of what you do. In any case, both are equally important. But they are, however, different.
Deciding on which is better does come down to what your goals are. For example, exercises that emphasize concentric contraction can be good for specific sports skills or to build explosive power, whereas exercises that focus on eccentric contractions with heavier loads can build strength and really breakdown a muscle.
While for general movement training, you can't have one without the other, there are some tricks and techniques that you can use to only focus on either concentric or eccentric contraction for the primary movers.
We will get into that, but first, let's quickly go over concentric vs eccentric contraction, which is better for:
- Hypertrophy
- Strength
- Power
- Rehabilitation
By understanding this, you will know the reason behind doing concentric lifts and eccentric lifts, or simply emphasizing one of the two during a standard exercise.
FOR HYPERTROPHY:
A lot of people want to build muscle, whether that be for their respective sport or just to look better.
If you want to build muscle, both the concentric and eccentric phases are important.
However, studies do show that eccentric contraction is slightly better for muscle hypertrophy. This is because more damage (microtears) occurs to the muscle when stretching it.
So, don't get lazy on the eccentric and move too quickly.
Related: How to Build Muscle Mass Without Fail
Prepare to maximize your gains with our exclusive 12-week hypertrophy training program. Choose between a 4 or 5 day training split and gain 2-12 pounds of muscle over 90 days...
FOR STRENGTH:
Strength and hypertrophy (building muscle) go hand in hand. The stronger you are, the more potential you have for gaining mass. So, if you think gaining strength is only for those who need it for their sport, that's wrong.
What's more, the stronger your muscles are, the more resilient your body is to injury.
When it comes to strength, studies show that regularly emphasizing the eccentric phase will lead to greater strength and neural adaptions.
Yes, you will gain strength in the concentric phase too, but the eccentric phase proves to have greater potential. This is due to the ability to use heavier loads for eccentric lifts.
So if you want to gain strength, you need to take the eccentric phase serious and implement negatives like bench press negatives and moving very slowly as you lower the barbell down on deadlift or squat.
This eccentric focused exercise is a very easy way to make your muscles stronger, but can lead to DOMS. Soreness is a part of the muscle building process, and is a measure of growth.
Related: How to Improve Strength
Note: For strength, isometric exercises are also great. Isometric exercises show to provide superior joint angle specific strength than dynamic strength training. They can even help lower blood pressure.
Prepare to maximize your strength with our exclusive 13-week strength training program. 3, 4, and 5 day per week programming options.
FOR POWER:
Power is very important for athletes. It should be noted that strength and power are different. Strength is about lifting the absolute maximum weight, whereas power is about maximal speed. So, think explosiveness.
To improve your power, you will have to start focusing on your concentric contractions. This is where power is built, the concentric phase.
If you think about it, it is quite obvious, how can you be explosive through stretching. That sounds like a recipe for injury anyway.
Since power is extremely important in Olympic lifting, and many Olympic lifts only focus on the concentric phase (they drop the barbell down on certain lifts), a lot of Olympic lifters do concentric lifts. The same is true for some of powerlifting. They usually drop their weights after a deadlift, as they don’t even want to bother with the eccentric part of the exercise.
So if you’re looking to increase your power, you'll need concentric lifts. However, like strength helps hypertrophy and hypertrophy helps strength, to build greater power, you need more strength, so you can't only focus on concentric lifting. They all go hand-in-hand-in-hand.
FOR REHABILITATION & PREHABILITATION:
Physiotherapy is one of the many ways that doctors can help people recover physically from an injury. And when they are rehabilitating patients, professionals will always focus more on eccentric exercises to help quicken the recovery process. In fact, many times they only focus on eccentric exercises.
Eccentric exercises tend to exert the most force with the least amount of movement. Therefore, they are also very safer to perform, especially with just the bodyweight alone or light weights.
So by doing eccentric exercises, they can help injured people regain strength in a safer manner.
Eccentric exercises are also fantastic for athletes who want to do "prehab" exercises (ensure they don't get injured in the first place). One example of this is nordic hamstring curls, which is an exclusively eccentric movement.
This can be especially helpful for older individuals who are incapable of going through the concentric phases of an exercise.
One of the most popular types of injuries that eccentric exercises are most effective with are Anterior Cruciate Ligament (ACL) injuries. Since concentric exercises will put a lot of pressure on the ligaments and joints, they can do more harm than good. But when the patient only has to do eccentric exercises, they can easily work around their injury.
One the flip side, when dealing with heavy weight or explosive movements, lengthening contractions (eccentric) are most likely to cause injury or increase the severity of an injury. So, you need to be careful with the eccentric phase. If you think about it, this also makes sense. You are lengthening a muscle and if you do so too fast or under too much load, you can tear the muscle.
Think about sprints, you'll often hear people hurt their hamstrings. This is often because they did not properly warm up, OR because they went to hard during the sprint and on the eccentric phase of the sprinting movement, they tore their muscle.
It may sound contradicting, but eccentric exercise is best for rehab, but it also has a greater potential for injury for healthy individuals who lift or play sport.
Now, let's go over how you do exercises that focus on concentric contraction and exercises that focus on eccentric contraction...
HOW TO DO CONCENTRIC LIFTS
There are various ways that you can do an exercises that would be considered a concentric lift.
The most obvious is doing you usual exercises but with a slower tempo on the concentric and as fast as safely possible on the eccentric.
Conversely, you could speed up the concentric phase using as much explosion as possible to try to create maximal speed power.
Now, in terms of really being a concentric only lift, you need to get creative in some cases.
An obvious way to do a concentric lift is with the deadlift. You simply lift the bar up and when you reach a standing position, you drop the weight (note: to do this, you should be using bumper plates and an Olympic barbell, along with doing it on thick rubber mat flooring).
Another idea is to place a barbell on safety catchers in a squat rack and starting the squat from the bottom position and doing 1 rep max's where you rack the weight at the top each set.
With any concentric lift like this, which there are many ways to get creative, you can only do one rep or else you will have no choice but to perform the eccentric phase (although you could have spotters help you to lower the weight down or use your own body in some way to make the eccentric phase easy, i.e. use your opposite arm to assist in lowering the weight back down after a one arm curl).
That said, when it comes to concentric lifts, if you are really focusing on power, then one rep max lifts make the most sense anyway. As for building muscle, simply slowing down the tempo of the concentric phase and keeping the eccentric phase is perfect.
HOW TO DO ECCENTRIC LIFTS
Eccentric lifts or exercises are the exact opposite of concentric lifts. They will allow you to put in the most force with the least effort. These are usually exercises that focus on specific muscle groups and help increase muscle mass and strength.
Like with concentric lifts, the easiest method of making an excerise "eccentric" is to slow down the eccentric phase as much as possible.
For example, you could do a 5 second negative on deadlift, bench press, or squat...or any other exercise for that matter.
This is very effective for building strength and muscle mass. You will see big gains if you implement this tempo into your training regularly.
Negatives are also great for beginners who can't do certain bodyweight exercises. It's always the concentric phase that makes bodyweight exercises impossible for beginners.
For example, if you can't do a pull up or push up, you can still perform the negative movement of it to start to build strength up in that exericse. With the pull up, you just jump up or get on a chair to start from the top and go down as slowly as possible and then when you get to the bottom, you repeat for each rep. The same is true for push ups. You'll be surprised how quickly you gain strength and can do a full proper pull up and push up with this technique.
As for eccentric only lifts, you just need to make certain set ups or have spotters.
For example:
- You can load up max weight on a barbell (after you are warmed up) and unrack the weight and lower it down slowly to the safety catches in a squat rack for eccentric squats (again, only one rep max for this one).
- You can set up a barbell at hip height so you can do eccentric deadlifts.
- You can do eccentric bench press by having a spotter only help you on the concentric phase (you could have two spotters so you don't have to do any work on the concentric phase because they lift it for you, which would allow you to do multiple reps.
You can even do eccentric and concentric only lifts by utilizing some machines.
The longer you are in the weightlifting and strength training game, the more creative you will get to achieve greater gains.
BENEFITS OF CONCENTRIC TRAINING
Emphasizing the concentric phase of your exercises can prove to be very effective and beneficial for specific reasons. Here are a few benefits that come with focusing on concentric training specifically.
Advantages:
First of all, by slowing down your concentric phase, you will increase the time under tension for your muscles, which will lead to greater muscle gains.
If you speed up the tempo to focus on explosiveness, you'll get the incredible advantage of an increase in power. Despite having less muscle density than a bodybuilder, powerlifters can easily outlift them. And the main reason for that is because powerlifters focus specifically on concentric movements. Some even skip eccentric movements entirely to maximize the effectiveness of their workout.
Note: Be careful when doing explosive exercises. Moving quickly is a lot more risky then moving slowly.
Concentric contraction can also increase the cardiovascular impact of your workout because it requires more oxygen. This is why cardio workouts focus more on explosive movements, which make your heart stronger by making it beat faster.
Concentric exercises are also great if you are a sprinter by increasing your speed without building too much muscle mass. You can also perfect your form when you start focusing on concentric movements, as that is how to initiate most exercises.
Finally, concentric contraction doesn't create much soreness because it doesn't cause microtears like eccentric (lengthening) contractions. If you were to do a concentric only workout, you'll likely not be sore at all the next day.
Disadvantages:
Focusing exclusively on your concentric contractions, you will not be able to accumulate as much muscle mass and strength.
Furthermore, if you are doing explosive concentric exercises, you'll have a greater likelihood of injury.
How to implement it into your training routine?
Implementing a concentric-emphasized approach to your workouts can be fairly easy. Since you’re already performing concentric movements during your workouts, you just need to slow them down.
Therefore, all you have to do is adjust how you workout and you can even continue to do the same exercises.
If your routine focuses on pushups, then try to be slower on your descent. The resistance should make the exercise more intense. And if you are performing squats, try to raise the barbell as slowly as you can.
As for explosive movements and one rep max concentric power lifts, implement them into your routine once a week. You don't have to overdo it on these. Several sets of each per week is enough to start. Maybe you have one day where you focus on a few explosive exercises and then once a month you do one rep max's after your main workout or just once you are warmed up (and have done plenty of warm up sets).
BENEFITS OF ECCENTRIC TRAINING
Eccentric training is often way underutilized and appreciated by newbies. It's extremely important that you emphasize the eccentric phase in your training, and here's why...
Advantages
The best thing about eccentric training is that it will help you build tremendous strength and muscle mass.
With the added strength, you will also be able to lift more and be stronger in the concentric phase. Thus, you will become more powerful too.
Muscles are strongest when they are in an eccentric state, which means you will be able to use a slow tempo and heavy loads. This will create microtears that need to be repaired through protein synthesis. In other words, you are going to see some serious gains.
Eccentric focused exercises are also a great way to give your body a metabolic boost, which can help burn calories. Your resting metabolic rate skyrockets when slowing down the descent on your lifts. So even when resting, you can continue burning calories for up to 72 hours.
Another benefit, which relates back to being stronger, is that you will significantly lower your risk of injury. This is why athletes particularly emphasize eccentric training.
Disadvantages
There are only two things to consider when it comes to "disadvantages" of eccentric training.
First, eccentric contraction is the main causer of DOMS. Delayed onset Muscle Soreness, or DOMS, is a very common condition that everyone who workouts experiences. DOMS is likely a sign that your muscle fibers ripped when exercising and are now will build back stronger (as long as you eat right). But even if it is healthy, that doesn’t make it any less painful.
With eccentric focused training, you will get really sore, which means you will be able to train the muscle group less frequently. However, as long as you have a good training split and recovery practices, this is a non-issue...unless you hate being sore. If you do hate being sore, don't worry, you will learn to appreciate it.
The other potential downfall is that eccentric training (lengthening contraction) is the most likely to cause injury, such as strains. So, you need to train smart, not just hard. You need to understand your limits and not overdo it in terms of volume or intensity. Use progressive overload and work your way up over time and all will be stellar.
How to implement it into your training routine
Implementing eccentric workouts into your training routine is usually easy and seamless. Just reduce the pace at which you descend, and you will be able to get all of the benefits that come with an eccentric training routine.
On top of that, implement some negative exercises with the help of spotters or specific set ups so you can really go heavy on certain lifts. As you can handle more weight with eccentric contraction, you can go heavier than you would with the exercise normally since you will only be focusing on the eccentric phase.
In terms of heavy negatives, don't overdo it. Start with just a couple sets a week with just several reps and work your way up in volume from there.
KEY TAKEAWAYS
- Eccentric and concentric muscle contractions are two parts of isotonic movements
- Isotonic movements involve shortening and lengthening of the muscle when under tension from an external load or some form of resistance.
- Isometric is the process of creating tension in the muscle without any movement (i.e. static holds).
- Concentric movements occur when the muscles contract (shorten), and eccentric movements occur when the muscles lengthen.
- Concentric movements can be explosive and quick, often allowing more power to people who exercise with it often, or it can be done slowly for increased time under contraction tension.
- Eccentric movements allow for better muscle growth and strength. The best way to employ eccentric training is by slowing down your negative movements.
- Eccentric contraction is known for its rehabilitating benefits, as people recovering from physical injuries usually take up eccentric focused exercises.
- Eccentric movements can cause severe DOMS, which can be very distracting and can make it hard to go about your regular day.
- Include isometric, eccentric, and concentric exercise to be the most well rounded as possible in your fitness.
WHY YOU SHOULD FOCUS ON CONCENTRIC, ECCENTRIC & ISOMETRIC CONTRACTION IN YOUR TRAINING?
Through this guide we have walked you through all of the benefits that come with using concentric and eccentric contraction. But we didn't really emphasize the importance of isometric contraction, which is to gain strength at specific ranges in a movement.
We highly recommend that you treat all three types of contractions equally to get the most from your training. By doing so, you will have very well rounded fitness - meaning you will be strong, muscular, powerful, and resilient to injury.
The good thing is, all three types of muscle contractions are easy to do in a single exercise. Using a push up as an example, you could do a very slow eccentric phase, an explosive concentric phase and on the last rep, you could hold the middle of the push up for 10+ seconds or until failure. This is a perfect example of emphasizing all three phases without needing to spend tons of extra time working out.
If you have any questions about concentric, eccentric, or isometric contractions, or muscle contractions and workouts in general, please feel free to reach out to us or peruse our blog as we have tons of resources available to learn how to get the most out of your training. Battle on!
Garett Reid
Author